Award-winning Nature journalist Pearson chronicles a series of groundbreaking longitudinal, cradle-to-grave birth-cohort studies begun by British scientists in the aftermath of World War II.
At a time when there was still food rationing and a major housing shortage, there was particular concern about how mothers and infants were faring. During one week in March 1946, the first of these studies surveyed 13,687 mothers who filled out a questionnaire on their experience of pregnancy and the health of the newborns. Not surprisingly, class differences proved to be determining factors in premature birth: “babies in the lowest class were 70% more likely to be born dead that those in the most prosperous, and they were also far more likely to be born prematurely.” These results were influential in the 1948 launch of the National Health Service, which provided better free maternity care and provisions for high-risk births. This study was followed by four other studies, in 1958, 1970, 1991, and 2000, with another one possibly in the offing. Over the 70 years since the first one, scientists have kept track of the cohorts, recording data on health, longevity, and social mobility. The correlation with class still persists, but scientists are now planning to analyze data from the 1958 cohort to determine “what factors in middle and old age…can reverse the effects of disadvantage in early life.” Comparisons between the cohorts are also enlightening. For example, obesity loomed as a problem in the 2000 study, which showed that 23 percent of children were either overweight or obese by age 3. The same study also looked closely at the quality of parenting, including the birth experience and whether or not the infant was breast-fed. Thankfully, in the digital age, cohort studies are easier to process, making more fine-tuned analysis possible.
A valuable mine of information of particular interest to social scientists, medical professionals, and concerned citizens who seek to influence social policy.